Aircraft collision risk determination

Abstract

A method of determining an aircraft's risk of collision at a candidate position includes determining the candidate position which the aircraft is capable of traversing to within a time period, based on the aircraft's: i) initial position; ii) initial trajectory; and iii) maneuverability. The method also includes determining a probability that the aircraft will traverse to the candidate position, and determining a presence of any collision hazards at the candidate position. A risk of collision is determined based on the determined probability that the aircraft will occupy the candidate position, and the determined presence of any collision hazards.

What is claimed is: 
     
         1 . A method of determining an aircraft's risk of collision at a candidate position, the method comprising:
 determining the candidate position to which the aircraft is capable of traversing within a time period, based on:
 an initial position of the aircraft; 
 an initial trajectory of the aircraft; and 
 a maneuverability of the aircraft; 
   the method further comprising:
 determining a probability that the aircraft will occupy the candidate position; 
 determining a presence of any collision hazards at the candidate position; and 
 determining the aircraft's risk of collision at the candidate position based on:
 the determined probability that the aircraft will occupy the candidate position; and 
 the determined presence of any collision hazards at the candidate position. 
 
   
     
     
         2 . The method as claimed in  claim 1 , wherein determining the probability that the aircraft will occupy the candidate position is based on the initial trajectory of the aircraft. 
     
     
         3 . The method as claimed in  claim 1 , wherein the candidate position lies on a first candidate trajectory; and
 wherein determining the probability that the aircraft will occupy the candidate position comprises:
 using a probability distribution to distribute a probability between a plurality of candidate trajectories, the plurality of candidate trajectories comprising the first candidate trajectory. 
   
     
     
         4 . The method as claimed in  claim 1 , wherein determining the probability that the aircraft will occupy the candidate position comprises using a Gaussian probability distribution. 
     
     
         5 . The method as claimed in  claim 1 , wherein determining the presence of any collision hazards at the candidate position comprises:
 determining a probability of one or more collision hazards being present at the candidate position based on positional data for one or more collision hazards; and   wherein determining the aircraft's risk of collision at the candidate position is further based on:
 the probability of any collision hazard being present at the candidate position. 
   
     
     
         6 . The method as claimed in  claim 1 , wherein determining the presence of any collision hazards at the candidate position comprises:
 determining whether any dynamic collision hazards are expected to traverse the candidate position based on positional data for one or more dynamic hazards and trajectory data for the one or more dynamic hazards.   
     
     
         7 . The method as claimed in  claim 6 , wherein the method comprises determining an expected time of presence at the candidate position for any dynamic collision hazards based on the positional data for the one or more dynamic collision hazards and the trajectory data for the one or more dynamic collision hazards; and
 wherein determining the aircraft's risk of collision at the candidate position is further based on:
 the expected time of presence of any dynamic collision hazards expected to occupy the candidate position. 
   
     
     
         8 . The method as claimed in  claim 1 , wherein the method comprises determining an expected time of presence of the aircraft at the candidate position based on:
 the initial position of the aircraft;   the initial trajectory of the aircraft; and   the initial speed of the aircraft; and   wherein determining the aircraft's risk of collision at the candidate position is further based on:
 the expected time of presence of the aircraft at the candidate position. 
   
     
     
         9 . The method as claimed in  claim 1 , wherein determining the probability that the aircraft will occupy the candidate position is based on a distance between the aircraft's initial position and the candidate position. 
     
     
         10 . The method as claimed in  claim 1 , wherein determining the probability that the aircraft will occupy the candidate position is based on an initial speed of the aircraft. 
     
     
         11 . The method as claimed in  claim 1 , wherein the method comprises providing a risk indicator based on the aircraft's determined risk of collision at the candidate position. 
     
     
         12 . The method as claimed in  claim 1 , wherein the method is repeated at a plurality of time intervals. 
     
     
         13 . The method as claimed in  claim 1 , wherein the method is repeated for each of a plurality of candidate positions to which the aircraft is capable of traversing within the time period, so as to determine a risk of collision at each of the plurality of candidate positions. 
     
     
         14 . The method as claimed in  claim 13 , comprising determining the aircraft's risk of collision within a region based on the risk of collision for a plurality of candidate positions within the region. 
     
     
         15 . The method as claimed in  claim 3 , wherein determining the presence of any collision hazards at the candidate position comprises:
 determining a probability of one or more collision hazards being present at the candidate position based on positional data for one or more collision hazards; and   wherein determining the aircraft's risk of collision at the candidate position is further based on:
 the probability of any collision hazard being present at the candidate position. 
   
     
     
         16 . The method as claimed in  claim 3 , wherein determining the presence of any collision hazards at the candidate position comprises:
 determining whether any dynamic collision hazards are expected to traverse the candidate position based on positional data for one or more dynamic hazards and trajectory data for the one or more dynamic hazards.   
     
     
         17 . The method as claimed in  claim 16 , wherein the method comprises determining an expected time of presence at the candidate position for any dynamic collision hazards based on the positional data for the one or more dynamic collision hazards and the trajectory data for the one or more dynamic collision hazards; and
 wherein determining the aircraft's risk of collision at the candidate position is further based on:
 the expected time of presence of any dynamic collision hazards expected to occupy the candidate position. 
   
     
     
         18 . The method as claimed in  claim 3 , wherein the method comprises determining an expected time of presence of the aircraft at the candidate position based on:
 the initial position of the aircraft;   the initial trajectory of the aircraft; and   the initial speed of the aircraft; and   wherein determining the aircraft's risk of collision at the candidate position is further based on:
 the expected time of presence of the aircraft at the candidate position. 
   
     
     
         19 . The method as claimed in  claim 2 , wherein the candidate position lies on a first candidate trajectory; and
 wherein determining the probability that the aircraft will occupy the candidate position comprises:
 using a probability distribution to distribute a probability between a plurality of candidate trajectories, the plurality of candidate trajectories comprising the first candidate trajectory. 
   
     
     
         20 . A collision avoidance system for an aircraft, configured and arranged to determine an aircraft's risk of collision at a candidate position by:
 determining a candidate position to which the aircraft is capable of traversing within a time period, based on:
 an initial position of the aircraft; 
 an initial trajectory of the aircraft; and 
 a maneuverability of the aircraft; 
   determining a probability that the aircraft will traverse to the candidate position;   determining a presence of any collision hazards at the candidate position; and   determining the aircraft's risk of collision at the candidate position based on:
 the determined probability that the aircraft will occupy the candidate position; and 
 the determined presence of any collision hazards at the candidate position.